An integrated circuit including a micro-controller unit (MCU) can be configured to couple to multiple external signal sources, such as scanners, video cameras, audio input devices, sensors, and other data sources. Control of clocked external signal sources that provide input to an analog-to-digital converter (ADC) often includes logic circuitry, typically external to the MCU, along with internal timers and counters. Configuration of such logic circuitry uses additional input/output (I/O) and control functions in the MCU, including interrupts, clocking, and the like.